UIPstream.H

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/*---------------------------------------------------------------------------*\
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  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
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-------------------------------------------------------------------------------
    Copyright (C) 2011-2013 OpenFOAM Foundation
    Copyright (C) 2017-2022 OpenCFD Ltd.
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.
 
    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.
 
    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
Class
    Foam::UIPstreamBase
 
Description
    Base class for input inter-processor communications stream
    (ie, parallel streams).
    Not to be used directly, thus contructors are protected.
 
SourceFiles
    UIPstreamBase.C
 
\*---------------------------------------------------------------------------*/
 
#include "Pstream.H"
 
#ifndef Foam_UIPstream_H
#define Foam_UIPstream_H
 
#include "UPstream.H"
#include "Istream.H"
#include "DynamicList.H"
#include "PstreamBuffers.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                        Class UIPstreamBase Declaration
\*---------------------------------------------------------------------------*/
 
class UIPstreamBase
:
    public UPstream,
    public Istream
{
    // Private Member Functions
 
        //- Check buffer position against messageSize_ for EOF
        inline void checkEof();
 
        //- Prepare receive buffer by adjusting alignment
        inline void prepareBuffer(const size_t align);
 
        //- Read a T from the receive buffer
        template<class T>
        inline void readFromBuffer(T& val);
 
        //- Read count bytes of data from the receive buffer.
        //  Prior data alignment is done by prepareBuffer
        inline void readFromBuffer(void* data, const size_t count);
 
        //- Read string length and string content
        inline Istream& readString(std::string& str);
 
 
protected:
 
    // Protected Data
 
        int fromProcNo_;
 
        DynamicList<char>& recvBuf_;
 
        label& recvBufPos_;
 
        const int tag_;
 
        const label comm_;
 
        const bool clearAtEnd_;
 
        int messageSize_;
 
 
    // Protected Constructors
 
        //- Construct given process index to read from using the given
        //- attached receive buffer, optional communication characteristics
        //- and IO format
        UIPstreamBase
        (
            const commsTypes commsType,
            const int fromProcNo,
            DynamicList<char>& receiveBuf,
            label& receiveBufPosition,
            const int tag = UPstream::msgType(),
            const label comm = UPstream::worldComm,
            const bool clearAtEnd = false,   // destroy receiveBuf if at end
            IOstreamOption::streamFormat fmt = IOstreamOption::BINARY
        );
 
        //- Construct given buffers
        UIPstreamBase(const int fromProcNo, PstreamBuffers& buffers);
 
 
public:
 
 
    //- Destructor. Optionally clears external receive buffer.
    virtual ~UIPstreamBase();
 
 
    // Member Functions
 
        // Inquiry
 
            //- Return flags of output stream
            virtual ios_base::fmtflags flags() const
            {
                return ios_base::fmtflags(0);
            }
 
 
        // Read Functions
 
            //- Return next token from stream
            Istream& read(token& t);
 
            //- Read a character
            Istream& read(char& c);
 
            //- Read a word
            Istream& read(word& str);
 
            // Read a string
            Istream& read(string& str);
 
            //- Read a label
            Istream& read(label& val);
 
            //- Read a floatScalar
            Istream& read(floatScalar& val);
 
            //- Read a doubleScalar
            Istream& read(doubleScalar& val);
 
            //- Read binary block with 8-byte alignment.
            Istream& read(char* data, std::streamsize count);
 
            //- Low-level raw binary read
            Istream& readRaw(char* data, std::streamsize count);
 
            //- Start of low-level raw binary read
            bool beginRawRead();
 
            //- End of low-level raw binary read
            bool endRawRead()
            {
                return true;
            }
 
 
    // Positioning
 
        //- Rewind the receive stream position so that it may be read again
        virtual void rewind();
 
 
    // Edit
 
        //- Set flags of stream
        virtual ios_base::fmtflags flags(const ios_base::fmtflags)
        {
            return ios_base::fmtflags(0);
        }
 
 
    // Print
 
        //- Print stream description to Ostream
        void print(Ostream& os) const;
};
 
 
/*---------------------------------------------------------------------------*\
                           Class UIPstream Declaration
\*---------------------------------------------------------------------------*/
 
//- Input inter-processor communications stream
//- using MPI send/recv etc. - operating on external buffer.
class UIPstream
:
    public UIPstreamBase
{
    // Private Member Functions
 
        //- Initial buffer recv, called by constructor (blocking | scheduled)
        void bufferIPCrecv();
 
 
public:
 
    // Constructors
 
        //- Construct given process index to read from using the given
        //- attached receive buffer, optional communication characteristics
        //- and IO format
        UIPstream
        (
            const commsTypes commsType,
            const int fromProcNo,
            DynamicList<char>& receiveBuf,
            label& receiveBufPosition,
            const int tag = UPstream::msgType(),
            const label comm = UPstream::worldComm,
            const bool clearAtEnd = false,   // destroy receiveBuf if at end
            IOstreamOption::streamFormat fmt = IOstreamOption::BINARY
        );
 
        //- Construct given buffers
        UIPstream(const int fromProcNo, PstreamBuffers& buffers);
 
 
    //- Destructor
    virtual ~UIPstream() = default;
 
 
    // Member Functions
 
        //- Use all read methods from base
        using UIPstreamBase::read;
 
 
    // Static Functions
 
        //- Read buffer contents from given processor
        //  \return the message size
        static label read
        (
            const commsTypes commsType,
            const int fromProcNo,
            char* buf,
            const std::streamsize bufSize,
            const int tag = UPstream::msgType(),
            const label comm = UPstream::worldComm
        );
};
 
 
/*---------------------------------------------------------------------------*\
                         Class UIPBstream Declaration
\*---------------------------------------------------------------------------*/
 
//- Input inter-processor communications stream
//- using MPI broadcast - operating on external buffer.
class UIPBstream
:
    public UIPstreamBase
{
    // Private Member Functions
 
        //- Initial buffer recv via broadcast, called by constructor
        void bufferIPCrecv();
 
 
public:
 
    // Constructors
 
        //- Construct given process index to read from using the given
        //- attached receive buffer, optional communication characteristics
        //- and IO format
        UIPBstream
        (
            const commsTypes commsType,     
            const int rootProcNo,           
            DynamicList<char>& receiveBuf,
            label& receiveBufPosition,
            const int tag = UPstream::msgType(),  
            const label comm = UPstream::worldComm,
            const bool clearAtEnd = false,  
            IOstreamOption::streamFormat fmt = IOstreamOption::BINARY
        );
 
 
    //- Destructor
    virtual ~UIPBstream() = default;
 
 
    // Member Functions
 
        //- Use all read methods from base
        using UIPstreamBase::read;
 
 
    // Static Functions
 
        //- Wrapped version of UPstream::broadcast
        //  \return the message size
        static label read
        (
            const commsTypes commsTypes,    
            const int rootProcNo,           
            char* buf,
            const std::streamsize bufSize,
            const int tag = UPstream::msgType(),  
            const label comm = UPstream::worldComm
        );
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //